The properties of the beta batteries are compared, which are made on the basis of the different β-isotopes with beta decay. Tritium and Ni-63 make it possible to make β-sources of high activity, without harmful associated emissions, with low self-absorption, emitting high-energy β-electrons that penetrate deep into the semiconductor and generate a large number of electron-hole pairs. The efficiency of beta batteries needs to be analyzed based on the real energy distribution of β-electrons. It makes possible to obtain the real value of the energy absorbed inside the β-source, correctly estimate the amount of self-absorption of the β-electrons and part of the β-electronsthere is a penetrate into the semiconductor, the number of electrons and holes that are generated in the semiconductor, and the magnitude of the idling voltage. Formulas for these quantities are calculated in this paper.
The effects of Zn2+ stress on seed germination, seedling growth and chlorophyll content were studied in order to better understand the effect of heavy metal Zn on the growth and development of green plants. The concentration gradient of Zn2+ was 20, 50,100,150,200,300,500,700mg / L, and deionized water was used as control. The results showed that under the Zn2+ stress condition, the germination index of the rhubarb seeds increased with the increase of Zn2+ concentration. Germination potential, germination rate and germination index were the highest when Zn2+concentration was 100mg / L, the conductivity was the lowest at zinc concentration of 100mg / L, the root length, stem length and chlorophyll content of Zn2+ gradually reduced. The results showed that the amount of Zn2+ could promote seed germination, but the root length, bud length and chlorophyll content of seedlings could be affected by different degrees. The zinc fertilizer should be used in the production.
The flipped classroom (FC) model has long brought significant benefits to higher education, secondary, and elementary education, particularly in improving the quality and effectiveness of learning. However, the implementation of FC model to support elementary students in developing self-learning skills (autonomous learning, independent study, self-directed learning) through technology still faces numerous challenges in Vietnam due to various influencing factors. Data for the study were collected through direct questionnaires and online surveys from 517 teachers at elementary schools in Da Nang, Vietnam. Based on SEM analysis, the study identified factors such as perceived usefulness, accessibility, desire, teaching style, and facilitating conditions. The research findings indicate that factors like the perceived effectiveness of the model, teaching style, and facilitating conditions have a positive correlation with the decision to adopt the FC model. Therefore, to encourage the use of the FC model in teaching, it is essential to raise awareness of the model’s effectiveness, improve teaching styles, and create favorable conditions for implementation.
The effect of foliar treatment with brassinosteroid (BR) on gender distribution in flowers of walnut (Juglans regia L. cv. Chandler) was investigated. Grafted walnut saplings (‘Chandler’) on the wild walnut (Juglans regia L.) rootstock were planted into 70-liter pots with a soil: peat: perlite medium and grown in pots between 2016–2020. BRs (24-epibrassinolide; EBR and 22(S), 23(S)-homobrassinolide; HBR) were applied at a concentration of 1 mg L–1 for four consecutive years at the time of flower differentiation. The experimental design was completely randomized with three replicates. The results show that BR applications could alter the sexual distribution of the walnut’s flower. BRs application significantly increased the number of total flowers and female flowers per tree. The number of female flowers was also increased by the season. The highest number of female flowers (20.9) was observed in the trees in 2020 and the application of 1 mg L–1 of HBR. It was determined that the annual growth of the plant and the increase in the number of females and total flowers were positively related. The effect of BRs indicated that the response was BR-type specific.
Two kinds of solar thermal power generation systems (trough and tower) are selected as the research objects. The life cycle assessment (LCA) method is used to make a systematic and comprehensive environmental impact assessment on the trough and tower solar thermal power generation. This paper mainly analyzes the three stages of materials, production and transportation of two kinds of solar thermal power generation, calculates the unit energy consumption and environmental impact of the three stages respectively, and compares the analysis results of the two systems. At the same time, Rankine cycle is used to compare the thermal efficiency of the two systems.
The COVID-19 pandemic has instigated global lockdowns, profoundly altering daily life and resulting in widespread closures, except for essential services like healthcare and grocery stores. This scenario has notably intensified mental health challenges, particularly among children and adolescents. Influenced by a myriad of factors including developmental stages, educational backgrounds, existing psychiatric disorders, and socioeconomic status, the pandemic’s impact extends beyond the immediate health crisis. This paper critically examines the multifaceted effects of the pandemic on mental and physical health across various age groups. It highlights the increased incidence of stress, anxiety, and depression, underscoring the pandemic’s deep psychological footprint. Additionally, the paper explores the societal implications, from altered family dynamics and educational disruptions due to the shift to online learning, to workplace transformations. These changes have led to a mix of adaptive responses and adverse effects, including heightened domestic tensions and mental health issues. The paper also delves into the ethical challenges faced by medical professionals during this crisis, balancing urgent patient care with ongoing medical research and mental health considerations. This analysis aims to provide a comprehensive understanding of the COVID-19 pandemic’s extensive impact on health and society, emphasizing the importance of addressing mental health as a crucial component of the response strategy.
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